centos7 - What does this error message mean when compiling and installing git?

Question

Compile and install git2.8 on centos7.2 according to the documentation, https://git-scm.com/book/zh/v2/起步-安装-Git

When it ends, it displays as follows:

What do the two errors in the red box mean?

The installation documentation says:

I have already executed this command. Install docbook2x separately, the display is as follows:

[root@i001 git-2.8.0]# yum install docbook2x
Loaded plugins: axelget, langpacks
No metadata available for base
No metadata available for dockerrepo
No metadata available for elrepo
No metadata available for epel
No metadata available for extras
No metadata available for mariadb
No metadata available for nginx
No metadata available for remi
No metadata available for remi-php70
No metadata available for remi-php70-test
No metadata available for remi-safe
No metadata available for remi-test
No metadata available for rpmforge
No metadata available for rpmforge-extras
No metadata available for rpmforge-testing
No metadata available for salt-2015.8
No metadata available for updates
No package docbook2x available.
Error: Nothing to do

I tried 3 times, but the same error message was displayed. I don’t know what to do. I’ll repeat my installation steps, which are based on the documentation. Do you think there is any problem?
Step 1:

$ sudo yum install curl-devel expat-devel gettext-devel \
    openssl-devel zlib-devel

Step 2:

$ sudo yum install asciidoc xmlto docbook2x

Step 3:

 $ tar -zxf git-2.8.0.tar.gz
  $ cd git-2.8.0
  $ make configure
  $ ./configure --prefix=/usr
  $ make all doc info
  $ sudo make install install-doc install-html install-info

The problem occurs when executing make all doc info. Can anyone help me find out the reason?

Answer 1

Generate git help documentation, which requires docbook-2x. It is recommended to look at the INSTALL file in the source directory first. In addition, yours is obviously git 2.8, where does 5.3 come from?